724 MEP167 – Hamstring mechanics during running drills: implications for return to running

AbstractBackground Running drills refer to a variety of physical exercises designed to mimic specific aspects of the running gait cycle. Such drills are commonly prescribed during rehabilitation after hamstring strain injury, yet there is no evidence on how these drills should be implemented or progressed to return to running/sport. Objective To determine the biomechanical demands (length and force) that running drills place on the hamstrings. Design Cross-sectional.Setting Laboratory.Participants Convenience sample of n=20 (n=10 female, age = 25 ± 4 years; stature = 174 ± 8 cm, mass = 70 ± 10 kg) recreationally active (>150 minutes/week of moderate intensity activity) participants. Procedure 3D motion capture experiments were conducted on participants completing three trials each of 8 running drills: ankling (dribbling), A-skips, B-skips- C-skips, butt-kicks, side-shuffles, cariocas (grapevines), and straight-legged running. Main Outcome Measurements Musculoskeletal modelling was performed to compute the musculotendinous stretch (% length relative to anatomical position) and bodyweight (BW) normalised force of the biceps femoris long head (most commonly injured hamstring muscle) during the swing phase of each drill. Results B-skips had the highest average peak stretch (16.5%), followed by straight-legged running (14.8%), cariocas (9.1%), C-skips (8.8%), A-skips (8.6%), butt-kicks (7.5%), side-shuffles (6.5%) and ankling (5.1%). The average peak force was highest for butt-kicks (3.6 BW) and cariocas (3.5 BW), followed by A-skips (2.6 BW), side-shuffles (2.5 BW), C-skips (2.5 BW), B-skips (2.1 BW), straight-legged running (1.4 BW) and ankling (0.8 BW).Conclusions Running drills induced a range of demands on the biceps femoris long head. Clinicians may use this data to guide the prescription of running drills to progressively load the hamstrings to return to running/sport. Further work is need to verify the efficacy of running drills in reducing incidence of hamstring injury and re-injury. Download figure Open in new tab Download powerpoint Abstract 724 Figure 1